SV-225223r961038: Digital signatures assigned to strongly named assemblies must be verified. | Microsoft DotNet Framework 4.0 STIG SCAP Benchmark

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Assessment Title

Rule Text

Digital signatures assigned to strongly named assemblies must be verified.

Description

Discussion Text

A strong name consists of the assembly's identity, simple text name, version number, and culture information (if provided)--plus a public key and a digital signature. Strong names serve to identify the author of the code. If digital signatures used to sign strong name assemblies are not verified, any self signed code can be impersonated. This can lead to a loss of system integrity.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-000185SV-7438V-7055

References

DPMS Target Microsoft DotNet Framework 4-0 DISA DPMS Target Microsoft DotNet Framework 4-0 4213

Checks

DISA STIG (Manual Reference)

Use regedit to review the Windows registry key 
HKLM\Software\Microsoft\StrongName\Verification. 
There should be no assemblies or hash values listed under this registry key. If the StrongName\Verification key does not exist, this is not a finding.

If there are assemblies or hash values listed in this key, each value represents a distinct application assembly that does not have the application strong name verified.  

If any assemblies are listed as omitting strong name verification in a production environment, this is a finding.

If any assemblies are listed as omitting strong name verification in a development or test environment and the IAO has not provided documented approvals, this is a finding.

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

# Windows PowerShell
# Reconstructed from oval:mil.disa.fso.dotnet:def:2
# Digital signatures assigned to strongly named assemblies must be verified.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# No assemblies or hash values under HKLM\Software\Microsoft\StrongName\Verification
# registry_object (registry_test)
function test_1 {
  return (-not ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\StrongName\Verification' -Name '.*')))
}

if (test_1) {
  Write-Output "PASS"
} else {
  Write-Output "FAIL"
}

Assessment Script Powered by AISyntax-verified

A standalone PowerShell script to assess this control automatically. Review before running it in your environment.

Syntax-checked as valid PowerShell. Not executed here — running it for real needs the actual ms_dotnet_framework_4_0 target this check assesses.

# OVAL Definition: oval:mil.disa.fso.dotnet:def:2
$compliant = Test-Path -Path "HKLM:\SOFTWARE\Microsoft\StrongName\Verification" -ErrorAction SilentlyContinue -and (Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\StrongName\Verification" -ErrorAction SilentlyContinue).PSChildName.Count -eq 0
if ($compliant) { Write-Output "PASS"; Exit 0 } else { Write-Output "FAIL"; Exit 1 }

Remediation

Use regedit to remove the values stored in Windows registry key HKLM\Software\Microsoft\StrongName\Verification. There should be no assemblies or hash values listed under this registry key.

All assemblies must require strong name verification in a production environment.

Strong name assemblies that do not require verification in a development or test environment must have documented approvals from the IAO.